:root{
  --bg:#E2EEF1;--hero-top:#EEF6F8;--hero-bottom:#D6E8EE;--panel:#F6FBFC;--panel-2:#D3E5EA;--border:#C3D7DE;
  --accent:#3B49D1;--accent-2:#5C6CF0;--accent-dark:#2A35A3;--text:#172235;--text-muted:#4F6172;
  --success:#1F9D73;--warn:#D9861C;--error:#D64545;--white:#FFFFFF;--clear:transparent;
  --peri:#8E95EC;--teal:#5CC6C8;--apricot:#F7A06A;--lemon:#F4D873;--coral:#F07884;
  --peri-hi:#B3B8F4;--teal-hi:#8FD9DA;--apricot-hi:#FAC09A;--lemon-hi:#F9E7A6;--coral-hi:#F6A3AB;
  --peri-soft:#E3E5FB;--teal-soft:#D8F1F1;--apricot-soft:#FDE8DA;--lemon-soft:#FBF2CF;--coral-soft:#FCE0E3;--teal-ink:#2C8486;
  --glass:rgba(246,251,252,.74);--hl:rgba(255,255,255,.78);--hl-soft:rgba(255,255,255,.38);
  --hub-sheen:rgba(255,255,255,.24);--branch-under:rgba(255,255,255,.55);
  --edge-lo:rgba(23,34,53,.08);--sh-inset:rgba(23,34,53,.07);--sh-ink:rgba(23,34,53,.18);
  --sh-accent:rgba(59,73,209,.14);--sh-accent-near:rgba(59,73,209,.10);
  --sh-peri:rgba(84,92,214,.16);--sh-teal:rgba(28,136,140,.16);--sh-apricot:rgba(214,112,48,.16);--sh-lemon:rgba(184,146,24,.16);--sh-coral:rgba(204,70,92,.16);
  --flag-red:#D9474F;--flag-blue:#33489E;--flag-white:#FFFFFF;--flag-edge:rgba(23,34,53,.16);
  --font-display:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Apple SD Gothic Neo","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Malgun Gothic","Microsoft YaHei",system-ui,sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --weight-body:400;--weight-medium:500;--weight-semibold:600;--weight-bold:700;
  --text-xs:12px;--text-sm:14px;--text-nav:15px;--text-base:17px;--text-lede:20px;
  --text-h1:64px;--text-h2:36px;--text-h3:24px;
  --r-pill:999px;--r-card:28px;--r-node:16px;--r-hub:26px;--r-small:10px;--r-mini:7px;--r-mark:11px;--r-seat:36px;--r-float:18px;--r-icon:12px;--r-tight:8px;--r-round:50%;
  --gutter:24px;--content:1200px;--reading:820px;--header-height:72px;--anchor-offset:88px;--toc-offset:96px;
  --ease-out:cubic-bezier(.2,.7,.2,1);--speed:.2s;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:var(--anchor-offset)}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--font-body);font-size:var(--text-base);font-weight:var(--weight-body);line-height:1.6;-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
button,input,select,textarea{font:inherit}
button{cursor:pointer}
button,select,input,textarea{color:inherit}
button{border:0}
img{display:block;max-width:100%;height:auto}
svg{flex-shrink:0}
ul{list-style:none;margin:0;padding:0}
p{margin:0 0 1em}
h1,h2,h3,h4{font-family:var(--font-display);font-weight:var(--weight-bold);text-wrap:balance;overflow-wrap:break-word}
h1{font-size:clamp(52px,4.45vw,72px);line-height:1.1;letter-spacing:-.02em;margin:0 0 24px}
h2{font-size:var(--text-h2);line-height:1.25;letter-spacing:-.02em;margin:0 0 24px}
h3{font-size:var(--text-h3);line-height:1.3;margin:0 0 16px}
strong,b{font-weight:var(--weight-bold)}
small{font-size:var(--text-sm)}
[hidden]{display:none!important}
:where(a,button,summary,input,select,textarea,[tabindex]):focus-visible{outline:2px solid var(--accent);outline-offset:3px}
:where(button,[role="tab"],summary){min-height:24px;min-width:24px}
::selection{background:var(--peri-soft);color:var(--text)}
.wrap{width:100%;max-width:var(--content);margin-inline:auto;padding-inline:var(--gutter)}
.reading-wrap{width:100%;max-width:var(--reading);margin-inline:auto;padding-inline:var(--gutter)}
.section{padding-top:80px;padding-bottom:80px}
.section--panel{background:var(--panel)}
.section--groove{background:var(--panel-2)}
.section-head{max-width:var(--reading);margin:0 auto 40px;text-align:center}
.section-head p{color:var(--text-muted)}
.grid{display:grid;gap:24px}
.grid--three{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid--five{grid-template-columns:repeat(5,minmax(0,1fr))}
:where(.grid,.wrap,.reading-wrap,article,section,main,aside)>*{min-width:0}
.stack>*+*{margin-top:24px}
.row{display:flex;flex-wrap:wrap;align-items:center;gap:16px}
.center{text-align:center}
.muted{color:var(--text-muted)}
.mono{font-family:var(--font-mono);font-weight:var(--weight-semibold);letter-spacing:.01em;font-variant-numeric:tabular-nums}
.no-break{white-space:nowrap}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap;border:0}
.sprite{position:absolute;width:0;height:0;overflow:hidden}
.panel,.card{background:var(--panel);border-radius:var(--r-card);padding:28px;box-shadow:inset 0 0 0 1px var(--white),0 18px 40px var(--sh-accent-near)}
.panel--inset{background:var(--panel-2);box-shadow:inset 0 1px 4px var(--sh-inset)}
.prose{overflow-wrap:break-word}
.prose p,.prose li{line-height:1.85}
.prose h2{margin-top:56px}
.prose h3{margin-top:32px}
.prose ul{list-style:disc;padding-left:1.4em}
.prose ol{padding-left:1.5em}
.prose li+li{margin-top:10px}
.prose a:not(.btn){text-decoration:underline;text-underline-offset:4px}
code{font-family:var(--font-mono);font-size:.88em;overflow-wrap:anywhere;background:var(--panel-2);padding:2px 5px;border-radius:var(--r-tight)}
pre{max-width:100%;overflow-x:auto;padding:24px;background:var(--text);color:var(--panel);border-radius:var(--r-node)}
pre code{padding:0;background:var(--clear);color:inherit;white-space:pre;overflow-wrap:normal}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:10px;height:54px;padding:0 30px;border:0;border-radius:var(--r-pill);font-size:var(--text-base);font-weight:var(--weight-semibold);letter-spacing:.01em;text-align:center;transition:transform var(--speed),box-shadow var(--speed);flex-shrink:0;white-space:nowrap}
.btn svg{flex:none;width:18px;height:18px}
.btn--primary,.btn-primary{color:var(--white);background:linear-gradient(135deg,var(--accent),var(--accent-2));box-shadow:inset 0 1px 0 var(--hl-soft),0 2px 4px var(--sh-accent-near),0 18px 36px var(--sh-accent)}
.btn--primary:hover,.btn-primary:hover{transform:translateY(-2px);box-shadow:inset 0 1px 0 var(--hl-soft),0 3px 6px var(--sh-accent-near),0 22px 44px var(--sh-accent)}
.btn--ghost{color:var(--accent);background:var(--white);box-shadow:inset 0 0 0 1.5px var(--accent),0 10px 24px var(--sh-accent-near)}
.btn--ghost:hover{transform:translateY(-2px)}
.btn:active{transform:translateY(0)}
.btn:disabled,.btn[aria-disabled="true"]{opacity:.55;cursor:not-allowed;transform:none}
.btn--small{height:44px;padding-inline:22px;font-size:var(--text-nav)}
.topbar{position:relative;z-index:30;background:var(--hero-top)}
.topbar__inner{max-width:1280px;height:var(--header-height);margin:0 auto;padding:0 32px;display:flex;align-items:center;gap:24px}
.brand{display:inline-flex;align-items:center;gap:10px;font-family:var(--font-display);font-size:var(--text-lede);font-weight:var(--weight-bold);letter-spacing:-.01em;color:var(--text);flex-shrink:0;min-height:44px}
.brand__mark{width:36px;height:36px;border-radius:var(--r-mark);box-shadow:inset 0 1px 0 var(--hl),0 6px 14px var(--sh-accent);flex:none}
.brand__zh{font-weight:var(--weight-medium);color:var(--text-muted)}
.nav{margin-left:auto}
.nav__list{display:flex;align-items:center;list-style:none;margin:0;padding:4px;gap:2px;border-radius:var(--r-pill);background:var(--glass);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);box-shadow:inset 0 0 0 1px var(--white),0 6px 18px var(--sh-accent-near)}
.nav__link{display:block;padding:7px 15px;border-radius:var(--r-pill);font-size:var(--text-nav);font-weight:var(--weight-medium);line-height:24px;color:var(--text-muted);white-space:nowrap;transition:color var(--speed),background-color var(--speed)}
.nav__link:hover{color:var(--text);background:var(--white)}
.nav__link[aria-current="page"]{color:var(--white);background:linear-gradient(135deg,var(--accent),var(--accent-2));box-shadow:inset 0 1px 0 var(--hl-soft),0 6px 14px var(--sh-accent)}
.tools{display:flex;align-items:center;gap:8px;flex-shrink:0}
.lang-wrap{position:relative}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-width:44px;width:auto;height:40px;padding:0 12px;border:0;border-radius:var(--r-pill);background:var(--clear);color:var(--text-muted);font-size:var(--text-sm);font-weight:var(--weight-medium)}
.lang span{white-space:nowrap}
.lang:hover{color:var(--text);background:var(--glass)}
.lang svg{width:16px;height:16px}
.language-menu{position:absolute;right:0;top:calc(100% + 10px);min-width:180px;padding:8px;background:var(--panel);border:1px solid var(--border);border-radius:var(--r-node);box-shadow:0 18px 36px var(--sh-accent)}
.language-menu a{display:flex;align-items:center;min-height:44px;padding:8px 12px;border-radius:var(--r-small);font-size:var(--text-nav)}
.language-menu a:hover,.language-menu a[aria-current="true"]{background:var(--panel-2)}
.login{display:inline-flex;align-items:center;justify-content:center;height:40px;padding:0 22px;border-radius:var(--r-pill);background:var(--text);color:var(--white);font-size:var(--text-nav);font-weight:var(--weight-semibold);box-shadow:inset 0 1px 0 var(--hl-soft),0 8px 18px var(--sh-ink);transition:transform var(--speed);white-space:nowrap}
.login:hover{transform:translateY(-1px)}
.menu-toggle{display:none;align-items:center;justify-content:center;min-width:44px;min-height:44px;border-radius:var(--r-pill);background:var(--panel);color:var(--text)}
.menu-toggle svg{width:22px;height:22px}
.drawer{display:none}
html.nav-open{overflow:hidden}
.footer{background:var(--panel-2);padding-top:64px;padding-bottom:24px;box-shadow:inset 0 1px 0 var(--white)}
.footer__grid{display:grid;grid-template-columns:1.3fr 1fr 1.2fr .8fr;gap:40px}
.footer__brand p{max-width:320px;margin-top:20px;color:var(--text-muted)}
.footer__heading{font-size:var(--text-base);margin:0 0 16px;font-weight:var(--weight-bold)}
.footer__list{display:grid;gap:4px}
.footer__list a{display:inline-flex;align-items:center;min-height:32px;color:var(--text-muted);font-size:var(--text-nav);padding-block:4px}
.footer a:hover{text-decoration:underline;text-underline-offset:4px}
.footer__bottom{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:16px;border-top:1px solid var(--border);margin-top:40px;padding-top:24px;font-size:var(--text-sm);color:var(--text-muted)}
.footer__legal{display:flex;flex-wrap:wrap;gap:20px}
.footer__legal a{display:inline-flex;align-items:center;min-height:28px}
.reveal{transition:opacity .6s var(--ease-out),transform .6s var(--ease-out)}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
#server-status{position:relative;display:block;min-height:160px;width:100%;max-width:100%;overflow:hidden;margin-top:24px;margin-bottom:32px}
#server-status+*{margin-top:32px}
#server-status>*{min-width:0;max-width:100%}
.decorated{position:relative;overflow-x:clip}
@media(max-width:1199px){.topbar__inner{gap:16px;padding-inline:24px}.nav__link{padding-inline:10px}}
@media(max-width:1099px){
  .nav{display:none}.tools{margin-left:auto}
  .menu-toggle{display:inline-flex}
  .drawer:not([hidden]){display:block;position:absolute;left:0;right:0;top:100%;padding:16px var(--gutter) 24px;background:var(--panel);border-bottom:1px solid var(--border);box-shadow:0 20px 36px var(--sh-accent);max-height:calc(100dvh - var(--header-height));overflow-y:auto;overscroll-behavior:contain}
  .drawer a{display:flex;align-items:center;width:100%;min-height:44px;padding:10px 16px;border-radius:var(--r-small);font-size:var(--text-base)}
  .drawer a:hover,.drawer a[aria-current="page"]{background:var(--panel-2);color:var(--text)}
  .drawer__languages{border-top:1px solid var(--border);margin-top:16px;padding-top:16px}
  .footer__grid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .grid--five{grid-template-columns:repeat(3,minmax(0,1fr))}
}
@media(max-width:768px){
  :root{--gutter:16px;--header-height:64px;--anchor-offset:80px;--text-h2:28px}
  h1{font-size:40px;line-height:1.15}
  .topbar__inner{padding-inline:16px;height:var(--header-height)}
  .tools{margin-left:auto}
  .section{padding-top:56px;padding-bottom:56px}
  .grid--three,.grid--five{grid-template-columns:repeat(2,minmax(0,1fr))}
  .btn{height:50px;padding-inline:26px;font-size:16px}
}
@media(max-width:640px){
  .no-break{white-space:normal}
  .lang span{display:none}
  .topbar__inner{gap:8px}
  .tools{gap:4px}
  .login{padding-inline:16px}
  .brand{gap:8px;font-size:var(--text-base)}
  .brand__mark{width:32px;height:32px}
  .grid--three,.grid--five,.footer__grid{grid-template-columns:minmax(0,1fr)}
  .panel,.card{padding:24px}
  .tilt,[data-tilt]{transform:none}
  .decorated>*{max-width:100%}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation:none!important;transition:none!important}
  .reveal,.reveal.pending{opacity:1;transform:none}
}